package _23.waiguan;

class SubSystemOne {
    public void MethodOne()
    {
        System.out.println("子系统方法一");
    }
}
class SubSystemTwo {
    public void MethodTwo()
    {
        System.out.println("子系统方法二");
    }
}
class SubSystemThree {
    public void MethodThree()
    {
        System.out.println("子系统方法三");
    }
}
class SubSystemFour {
    public void MethodFour()
    {
        System.out.println("子系统方四");
    }
}